To authenticate a U.S. document for use in India, you must first obtain an apostille from the state that issued your document in the United States.
A document with an Apostille does not require additional certification by the U.S. Department of State or legalization by a U.S. embassy or consulate overseas to be recognized in a participating country.
Obtaining an Apostille
Documents issued in the United States must be authenticated before they can be recognized as valid in India. Examples of such documents are court documents, birth, death and marriages records, educational documents, incorporation papers and other legal papers. More Information
In the United States, each state issues apostilles for its own documents. For example, a California birth certificate must be authenticated with a California apostille. Similarly, a New York death certificate must be authenticated by an apostille issued by the state of New York. Each state maintains a website explaining how to obtain an apostille.